LT13129 - The classical viscous fingering problem is one of the most
studied among fluid dynamic systems, having a wide spectrum of
applications ranging from oil recovery processes to biodynamics of
living cells. Conventionally, it considers the injection of a fluid into
another of higher viscosity, at a constant injection rate, in narrow
channel passages. The result is the development of visually striking,
highly ramified interfacial patterns. Despite their visual appeal and
physical relevance, the emergence of such convoluted structures is not
always desirable. In fact, the search for mechanisms to prevent the
development of these complicated morphologies is of fundamental
importance to a number of areas in science and technology. Now, a group
of researchers has reported a remarkably simple solution for the problem
of minimizing the viscous fingering instability. Using a variational
technique they have shown that interfacial instabilities are
dramatically restrained if a time-dependent, linearly-increasing
injection rate is employed. Their analytic results are confirmed by
experiments and numerical simulations. This is illustrated in the
figure, where typical radial flow interfacial patterns are depicted if a
constant injection rate (left), or the optimal linearly growing
injection rate (right) is used.
Thursday, September 6, 2012
Minimizing viscous fluid fingering
LT13129 - The classical viscous fingering problem is one of the most
studied among fluid dynamic systems, having a wide spectrum of
applications ranging from oil recovery processes to biodynamics of
living cells. Conventionally, it considers the injection of a fluid into
another of higher viscosity, at a constant injection rate, in narrow
channel passages. The result is the development of visually striking,
highly ramified interfacial patterns. Despite their visual appeal and
physical relevance, the emergence of such convoluted structures is not
always desirable. In fact, the search for mechanisms to prevent the
development of these complicated morphologies is of fundamental
importance to a number of areas in science and technology. Now, a group
of researchers has reported a remarkably simple solution for the problem
of minimizing the viscous fingering instability. Using a variational
technique they have shown that interfacial instabilities are
dramatically restrained if a time-dependent, linearly-increasing
injection rate is employed. Their analytic results are confirmed by
experiments and numerical simulations. This is illustrated in the
figure, where typical radial flow interfacial patterns are depicted if a
constant injection rate (left), or the optimal linearly growing
injection rate (right) is used.
